1. Field of the Invention
This invention relates to filters and, more particularly, to a filter for separating impurities from a fluid.
2. Background Art
Fluid filters are used in a wide range of environments. In many applications, the medium being filtered is caustic and tends to degrade metal filter components. Accordingly, many filters are made with non-metal components which may vary in composition depending upon the nature of the fluid to be filtered.
The use of non-metal filters has presented a challenge to designers of these filters. The fluid being filtered may be directed through the filter at a relatively high pressure. Designers of these filter systems strive to develop systems that have the requisite filtering capacity at potentially high volume and pressures without fluid leakage to the outside environment.
A particular challenge in this respect has been the design of the main housing which defines the primary filtering chamber. To achieve the above ends, these housings have been made in the past from joined plastic components. In one such form, a cylindrical material is used to define the main filtering chamber. The bottom of the chamber, typically defining the fluid outlet, is sealed by a separate base plate which must be joined to the cylindrical stock material in such a manner that the connection is both mechanically of the requisite strength and capable of preventing leakage between the parts.
In one form, the invention is directed to a fluid filter having a housing assembly defining a chamber through which fluid to be filtered can flow between an inlet and an outlet, a filtering assembly within the chamber through which fluid moving between the fluid inlet and fluid outlet passes, and a cover assembly. The housing assembly has an opening through which at least a part of the filtering assembly can be directed into an operative position within the chamber. The cover assembly seals the opening. The housing assembly has a housing body and a base plate connected to the housing body. The base plate is secured to the housing body through at least one weld and a plurality of mechanical fasteners.
In one form, the housing body and base plate have cooperating portions that reside, one within the other, with the housing body and base plate operatively connected.
In one form, the housing body and base plate each have a central axis. The cooperating portions define a seam that extends continuously around the central axes. The at least one weld is formed at the seam.
The cooperating portions may be defined by a non-metal material, such as plastic.
The weld may likewise be defined by a non-metal material and may be the same as the non-metal material defining the cooperating portions.
In one form, the non-metal material is made from at least one of: (a) polyvinyl chloride (PVC); (b) polypropylene (PP); (c) chlorinated polyvinyl chloride (CPVC); and (d) polyvinylidene difluoride (PVDF).
In one form, the base plate defines the fluid outlet.
A second weld may be made over the at least one weld.
In one form, the at least one weld extends continuously around the central axes.
The at least one weld may be formed by a material that is initially separate from the cooperating portions.
In one form, the at least one mechanical fastener extends into the housing body and base plate.
The at least one mechanical fastener may be a threaded fastener, and in one form is a self-tapping fastener.
In one form, the cooperating portion on the housing body has an annular edge extending around a central axis and the at least one mechanical fastener extends into the annular edge.
In one form, the base plate has a stepped through bore with a larger diameter portion and a smaller diameter portion. The at least one mechanical fastener has an enlarged head and is directed through the through bore into the annular edge so that the enlarged head is countersunk within the larger diameter portion of the through bore.
In one form, the base plate is made from a non-metal material and the at least one mechanical fastener is spin-welded to the base plate.
A filler material may fill the larger diameter portion of the through bore.
In one form, there are a plurality of mechanical fasteners extending through the base plate into the annular edge.
In one form, the annular edge has a circumferential extent and the plurality of mechanical fasteners are spaced at prescribed intervals around the circumferential extent of the annular edge.
The prescribed intervals may be substantially equal.
In one form, 5-10 mechanical fasteners are used.
The housing body may be pre-drilled to receive the at least one mechanical fastener.
In one form, the filtering assembly has a wall structure capable of operatively supporting a filter material so that fluid to be filtered can pass through the filter material operatively supported by the wall structure as fluid to be filtered flows between the fluid inlet and fluid outlet.
The wall structure may define a perforate, cup-shaped receptacle.
The filtering assembly may further include a filter bag that is supported by the wall structure within the cup-shaped receptacle.